Means for cooling the pistons of heat engines



'i5 posed to'sea patetica Nov. is, i927.

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UNITED STATE-s-PArE'NrjOFFicE.

animi: A.. ernaar, or BROOKLYN, -Niiw Yon'x, AssIoNon To ernaar DEVELOPMENT ooiarANY, or novas. GitiinN, DEL-AWARE, A CORPORATION or iiitnnwlima` MEANS ron coonnvo Tim rIsToNs or naar ENGrNns.

Appiicauon .nien-April as, i922. serial No.- 556,784.

. pistons of heat engines, especially of pistons' of internal combustion .engines of .the autoigiiition type, in which a very .high -mean temperature is maintained. As is now well understood, the solution of this problem lies in abstracting heat from the headpf the piston as rapidly as possible. For this purpose,

it has been proposed to water cool the under io surface of the piston head, by circulating water through the interior of the piston from an external source. Thismethod' however involves the use of sliding parts, with its attendant oom lications. It has also been prolor confine within the piston a quid which may or may not completely fill the same.A As explained in in y prior apphcations for Letters Patent, Serial'No. 486,181

y for pistons for internal combustion engines,

filed July 20th, 1921, and 529,314, pistons for internal combustion engines, filed J anua 14th, 1922, such liquid acts to transfer spec ily the heat from the piston head to the side walls of the piston from whence it is oonducted by contact with the water cooled cyl- 'inder walls. This `method of conning'the liquid in a completely enclosed cavity inakhollow piston a so has serious drawbacks, first, since the li uid within the piston nat 3o urally becomes cated and will therefore create an increasing vapor pressurewithin the piston, which ma prove disastrous, and second, the liquid wit in the piston naturally churns up as the piston 4reciprocates rapidly and as the pressure increases, becomes so mixed with the air in the cavity that the liquid becomes very suds so to speak, and does not act so eective y `to abstract heat from the piston as if unmixed with air.

The' object of this invention is to overcome the defects of both es of cooling pistons above mentioned. urtlier objects will become apparent as the description' roceeds. Referrin to the drawin in whic what I now consi er the preferresforms of my invention are shown, Fig. 1 is a vertical section through -a hollow piston constructed according to my invention, together with the adjacent portions .w of the cylinder. 4

. Fig. `2is an enlarged `vertical section` through a portion of said `piston and the means employed for furnishing communicay` tion'betw'een the interior of the piston and lltheexteriorthereof.

The interior coolin shown, the valve is of the umbre a or petti- Fig. 3 is a section on line 3-3 of Fig. 2 looking in the direction of the arrows. i j

Fig. 4 isa detail showing the port in the piston affording connection with the outside open. y

The type of piston I have chosen to illus-- trate the invention is a large low pressure piston 1, in which the under surface 2 thereof is employed as a compressor forv precompressinor the intake air for. the engine. Both t e upper surface 3 and the under surface 2 are therefore working surfaces -which become more or lessheated durin the operation of the engine, although o course the upper surface is exposed to the reater heat. Said piston is as shown made ollow, so as to provide a space 4 `within the piston adapted to contain a liquid 5, j such as water, or .preferably oil, which possesses a higher boiling pointthan Water.

surface of the piston exposed to the was of the liquid may be' increased b means of ycoolin fins 6. Preferably the i uid only parta y fills the said space,- so t at it is alternately thrown against opposite ends of the piston as the piston reciprocates, thereby 'securing a very effective circulation -of the liquid. Instead of sealing the liquid within said chamber however, I prefer to provide a port 7 or a valve which leads outside of the piston, but which requires no sliding couplings. Said valve or port is shown as in the form of a tube? which extends within the piston to a oilit preferabl above the normallevel 8 o the liquid. Said tube also extends downwardly adjacent the bottom of the trunk 8 of the piston. A closure or valve 9 is fprovided for said, port, said valve being pre erably located within the iston. As

coat type so thattlie spray and lash o f the liquid will drain- 'off the over anging edge, and not enter the 4port 7" even when valve 9 is lifted. Said valve is with an elongited stem lvwhich extends. downwardly` t rough said tubegand is provided atits lower end with a'collar or an. abutment-11. Said stem is shown as ided within the tube adjacent its-upper an lower end b guide blocks 12,l 18 see Figs. -2 Preferably I remova ly support the tu 7 -on ,the piston asb mountingit; within a larger tube 14.` ev latter is 'V shoggp as extending through `a `.clamp 15 Il.

providtfigl.` 10o 4 out the tube 7 with the attached bolted to a projection 16 on the interior of the trunk 8 and also is threaded at 17 ,in the lower wall of the cavity'in the piston. Said outer tube is made of suiicient-diam- -eter to permit both the inner tube 7 and collars 11 and 18. Means are provided to open said valve whenever this may be done, without danger of permitting the liquid to escape 'from the interior of the piston. 'For this purpose, I provide means for opening the valve whenever the piston is near the end of its down stroke, at which time the liquid will obviously be collected in the bot.

tom of the cavity due to the usual rapid deceleration of the piston as it nears the end of its stroke. As shown, said means consists of an abutment 2O which is preferably adjustable as by being provided with a threaded stem 21. threaded in bracket 22 secured to the guide 23 of the engine. It will readily be seen that whenever the piston" approaches the limit of its down stroke,

the collar 11 will come in contact with abutment 20 and force the valve stem and valve 9 upwardly to open the valve. .This will .at once place the interior of the piston in communication with the atmosphere and relieve the piston from any excess air or vapor-pressure, without at the same time permitting any liquid to escape.` v It is of course obvious that the valve may be biased in the open position and made to close when the piston approaches the upper end of its stroke, if desired, this being merely a reversal of the o eration.

The normal evel of the 'liquid as shown vis about on the level with the top of the outer tube 14. Said tube ,therefore may act as a valuable means for gauging the amount of liquid within the piston. Thus in filling the piston, it may be filled until it begins to overflow from the pipe. Also the pipe 14 may be used to assist in illing, by removing from said pipe the inner pipe 7 and the valve 9. A small rubber hose may then` be .inserted through the pipe 14 andthe liquid forced therethrou h until the liquid -begins to overflow throng the pipe. If at any time it is desired to find` out whether the liquid within the iston has ybeen reduced below its 'proper leve it is simply necessary to take rts, and to. move the piston slightly, there y settin `up small waves in theliquld. If no liqui v then s lashes over into the tube 14, a vfalrly good indication-will be obtained that the liquid level vis materially below that of the top yof the tube and that 'additional liquid is required.

In accordance with vthe provisions of the patent statutes, I have herein described .the principle of operation of my invention', together withthe apparatus, which I now considerto represent the bestembodiment thereof, but I desire to have it understood that theapparatus shown is only illustrative and that the invention can be carried out by other means. Also, while it is designed to use the various features and elements in the combination and relations described` some of these may be altered and others omitted without interfering with the more general results outlined, and the invent-ion extends to such use.

Having herein described my inventlon what I claim and desire to secure by Letters Patent is,

1. A hollow piston for internal combustion engines adapted to contain a substantially unchanging body of liquid for l with a substantiall unchanging body of liquid for cooling t e same, a port leading from within said piston to the outside thereof, a valve normally closing said port and means for opening said valve when the liquid is ai, theopposite end of the -pistonfrom said 4. A hollow iston for vertical reciprocating engines a apted to be partially filled with a substantiall unchanging body of liquid for cooling t e same, a port iny said piston abovethe normal level of the liquid and means for closing said port when the liquid-is thrown upwardly above its normal eve 5. A hollow piston for internal combustion lengines adapted to be partially filled with a.

liquid, a port in said piston, a valve within 6. A piston for vertical heat engines having a cavity, and means for'filling said cavity with liquid/to a predetermined level comprising a tube carried by said piston and extending from without the piston up through said cavity to about said` predetermined liquid level and means for closing said tube.

7. A piston for vertical heat engines havin a cavit adapted to'contain a liquid, a tu e exten ing within said cavity above the normal liquid level, a valve for closing the upper end of the tube, a stem for said valve extending through the tube below the cavity, and an abutment against which said stem is adapted to strike on reciprocation of said piston.

8. A piston for vertical heat engines having a cavit adapted to contain a liquid, a tube extending within said cavity above the normal liquid level, a valve for closing the upper end of the tube, a stem for said valve extending through the tube belbw the cavity, a second tube secured tosaid piston, enclosing said first tube and extending within the piston to about the normal liq'uid level and an abutment a ainst which said stem is adapted to stri e on reciprocation of said piston.

9. A hollow piston for vertical reciprocating engines adapted to be partially lled with 'a liquid forcooling the same, a port in said piston above the normal level of the liquid and an umbrella valve for closingsaid port when the li uid is thrown upwardly above its normal evel.

10. A hollow piston for internal combustion engines adapted to be partially filled with a substantially unchanging body of liquid for cooling the same, means connecting the space above the liquid within said piston uid for cooling the same, and means for periodically permitting the reduction of vapor pressure in said plston without permitting,

the escape of liquid therefrom,

12. A hollow piston for internal combustion engines adapted to be partially filled4 with a substantially unchanging body of liquid for cooling the same, a port connecting the space above the liquid within said piston with the outside of said piston, a valve normally closing said port and means for periodically opening said valve to permit reduction of the vapor pressure within said piston.

In .testimony whereof I have aiiixed my signature.

ELMER A. sPERizY. 

